A French government plan to rescue Air France is contingent on the carrier scrapping domestic flights, the country's economy minister has said.
Air France should become "the most environmentally respectful airline", Bruno Le Maire told France Inter radio.
The government has approved a €7bn (£6.15bn) loan to Air France, which has been hit hard by coronavirus curbs.
On Monday, the European Commission approved the proposal, saying it met EU rules on state aid.
In his radio interview, Mr Le Maire said the coronavirus crisis provided an opportunity to "reinvent our model of economic development to ensure it is more respectful of the environment".
He added that this meant a number of Air France domestic routes would need to go – without giving details.
"When you can travel by train in less than two and a half hours, there is no justification for taking a plane," he said.
Like most airlines, Air France has drastically reduced its activities. The company is currently operating about 5% of its usual scheduled flights.
Last month, Air France-KLM secured at least €9bn in government aid, as the Franco-Dutch airline group struggles to stay afloat because of the coronavirus outbreak.